This invention relates to an image recording device utilizing a so-called transfer-type recording medium comprising a recording sheet on which a latent image corresponding to an image to be recorded is formed and a developing sheet on which a visible image is formed by transferring the image on the recording sheet to a surface of the developing sheet, and more particularly to a device having a function capable of erasing an any image on the recording sheet, for example, a visible negative image corresponding to the latent image having been remained after the visible image is formed.
Conventionally, the transfer-type photo and pressure sensitive recording medium, disclosed in, for instance Japanese Patent Provisional Publication SHO 58-88739 which had been filed by the Mead Corporation (the corresponding U.S. application is U.S. Pat. No. 4899209), has been known. This type of recording medium comprises a recording sheet on which a plurality of microcapsules, each containing a component for changing the rupture strength thereof when exposed to light and a dye-precursor, are coated, and a developing sheet on which a developer material reactable with the dye-precursor is coated.
A latent image corresponding to an image to be developed is primarily formed on the recording sheet, in other words, on a surface of the recording sheet, a figure of an area on which the rupture strength of the microcapsules are changed is determined based upon the image to be developed when the recording sheet is exposed to light. The exposed recording sheet and the developing sheet are pressurized in an overlapped state, and the microcapsules on the recording sheet are crushed in accordance with the figure formed on the recording sheet. Finally, the dye-precursor streamed out the crushed microcapsules react with the developer material to develop a visible image on the developing material sheet.
In this type of image recording device. It is possible to obtain a high-quality visible image with low-cost, than an image obtained by a so-called silver salt photographic system, or a toner image obtained by an electrophotographic system.
However, with the transfer-type image recording device described above, a recognizable image may remain on the recording sheet after the visible image is formed on the developing sheet. For example, a negative image formed by the uncrushed microcapsules is remained on the recording sheet in a visible state. Therefore, it is necessary to cut the recording sheet into pieces of shreds by using a shredder or to incinerate it, if the contents of the image formed on the recording sheet include a confidential matter. Thus, a treatment of the used recording sheet has become troublesome.